Enzymatic hydrolysis method for the conversion of C-7 sugar to C-7 hydroxyl taxanes

Abstract

An enzymatic hydrolysis method, wherein one or more C-7 sugar, preferably C-7 xylosyl-bearing taxanes are contacted with an enzyme or microorganism capable of hydrolyzing said sugar groups to hydroxyl groups.

What is claimed is: 
     
       1. A method for the preparation of at least one taxane of the following formula I containing a hydroxyl group directly bonded at C-7: ##STR8## where R 1  is hydroxyl or acyloxy; R 2  is acyloxy or hydroxyl; and   R 3  and R 4  are independently alkyl or aryl; or a salt thereof,     comprising the steps of contacting at least one taxane of the following formula II containing a xylosyl group directly bonded at C-7: ##STR9## where R 1 , R 2 , R 3  and R 4  are as defined above, and "xylosyl" is a xylosyl group directly bonded at C-7, or a salt thereof,   with a microorganism, or an enzyme obtained therefrom, capable of catalyzing the hydrolysis of said C-7 xylosyl group to said C-7 hydroxyl group, effecting said hydrolysis, and obtaining said at least one taxane containing a hydroxyl group directly bonded at C-7, wherein said microorganism belongs to a genus selected from the group consisting of Moraxella, Micrococcus and Bacillus.   
     
     
       2. The method of claim 1, wherein said taxane of the formula II is at least one taxane selected from the group consisting of 7-xylosyltaxol, 7-xylosyl-10-desacetyltaxol, 7-xylosylbaccatin III, 7-xylosyl-10-desacetylbaccatin III, 7-xylosyl cephalomannine, 7-xylosyl-10-deacetylcephalomannine, 7-xylosyltaxol C, and 7-xylosyl-10-deacetyltaxol C; and said taxane of the formula I is at least one taxane selected from the group consisting of paclitaxel, 10-desacetyltaxol, baccatin III, 10-desacetylbaccatin III, cephalomannine, 10-deacetylcephalomannine, taxol C, and 10-deacetyltaxol C. 
     
     
       3. The method of claim 1, wherein the xylosyl-bearing taxane starting material employed in said hydrolysis method comprises a mixture of xylosyl-bearing taxanes. 
     
     
       4. The method of claim 3, wherein said mixture of manes is obtained by plant cell culture of plant tissue, wherein said plant is a member of the Taxus genus. 
     
     
       5. The method of claim 1, wherein a microorganism is employed which belongs to one of the following genera: Moraxella, Micrococcus or Bacillus. 
     
     
       6. The method of claim 5, wherein said microorganism is selected from the group consisting of Moraxella sp. ATCC 55475, Bacillus macerans ATCC 55476, Bacillus circulans ATCC 55477, and Micrococcus sp. ATCC 55478. 
     
     
       7. The method of claim 1, wherein an enzyme is employed which is obtained from a microorganism belonging to one of the following genera: Moraxella, Micrococcus or Bacillus. 
     
     
       8. The method of claim 7, wherein said enzyme is obtained from a microorganism selected from the group consisting of Moraxella sp. ATCC 55475, Bacillus macerans ATCC 55476, Bacillus circulans ATCC 55477, and Micrococcus sp. ATCC 55478. 
     
     
       9. The method of claim 1, wherein (i) the taxane product obtained by said method is paclitaxel, or (ii) the taxane product obtained by said method is an intermediate useful for paclitaxel synthesis and said method comprises the further step of converting said intermediate to paclitaxel. 
     
     
       10. The method of claim 3, wherein said mixture of taxanes is obtained by extraction from plant tissue, wherein said plant is a member of the Taxus genus. 
     
     
       11. The method of claim 1, wherein (i) the taxane product obtained by said method is a C-13 acyloxy sidechain-bearing taxane, or (ii) the taxane product obtained by said method is an intermediate useful for the synthesis of a C-13 acyloxy sidechain-bearing taxane and said method comprises the further step of converting said intermediate to a C-13 acyloxy sidechain-bearing taxane. 
     
     
       12. The method of claim 2, wherein said taxane of the formula I is at least one taxane selected from the group consisting of paclitaxel, baccatin III, 10-desacetyl baccatin III and cephalomannine.